About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
DSN-W 2012
Conference paper
On limitations of using cloud storage for data replication
Abstract
Cloud storage services often provide a key-value store (KVS) functionality, an object-based interface for accessing a collection of unstructured data items or blobs. Every blob is associated with a key that serves as identifier to access the blob. In the simplest form, a key-value store provides only methods for writing and reading an entire blob, for removing blobs, and for listing all defined keys. On the other hand, many existing schemes for replicating data with the goal of enhancing resilience (e.g., based on quorum systems) associate logical timestamps with the stored values, in order to distinguish multiple versions of the same data item. This paper uses the consensus number of a shared storage abstraction as a measure for its power to facilitate the implementation of data replication. It is demonstrated that a KVS is a very simple primitive, not different from read/write registers in this sense, and that a replica capable of the typical operations on timestamped data is fundamentally more powerful than a KVS. Hence, data replication schemes over storage providers with a KVS interface are inherently more difficult to realize than replication schemes over providers with richer interfaces. © 2012 IEEE.